Bismuth (bi) Or Thallium (tl) Containing Patents (Class 505/492)
  • Patent number: 8637433
    Abstract: A method for making a composite superconductor and a superconductor made using the method. Superconducting filaments are embedded in a matrix material. Oxygen-containing elements are also embedded in the matrix material, with the oxygen-containing elements preferably being dispersed evenly among the superconducting filaments. A surrounding reinforcement material contains the other elements and preferably seals the superconductor from the surrounding atmosphere.
    Type: Grant
    Filed: October 4, 2011
    Date of Patent: January 28, 2014
    Assignee: Florida State University Technology Transfer Office
    Inventors: Thomas Painter, Ting Xu, Xiaotao Liu
  • Patent number: 8530389
    Abstract: An improved process for the preparation of oxide superconducting rods. The present invention provides a process for the preparation of oxide superconducting rods. The process includes the steps of a cold isopressing process without addition of binder, particularly thin and those based on Ag-added (Bi,Pb)2 Sr2 Ca2 Cu3 O10+x is disclosed.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: September 10, 2013
    Assignee: Council of Scientific & Industrial Research
    Inventors: Narinder Kumar Arora, Gursharan Kaur Padam, Ramesh Sethi, Mukul Sharma, Shrikant Narayan Ekbote
  • Publication number: 20110045985
    Abstract: A superconductor which comprises a new compound composition substituting for perovskite copper oxides. The superconductor is characterized by comprising a compound which is represented by the chemical formula A(TM)2Pn2 [wherein A is at least one member selected from the elements in Group 1, the elements in Group 2, or the elements in Group 3 (Sc, Y, and the rare-earth metal elements); TM is at least one member selected from the transition metal elements Fe, Ru, Os, Ni, Pd, or Pt; and Pn is at least one member selected from the elements in Group 15 (pnicogen elements)] and which has an infinite-layer crystal structure comprising (TM)Pn layers alternating with metal layers of the element (A).
    Type: Application
    Filed: February 20, 2009
    Publication date: February 24, 2011
    Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCY
    Inventors: Hideo Hosono, Hiroshi Yanagi, Toshio Kamiya, Satoru Matsuishi, Sungwng Kim, Seok Gyu Yoon, Hidenori Hiramatsu, Masahiro Hirano, Yoichi Kamihara, Takatoshi Nomura
  • Patent number: 7541313
    Abstract: A alloy (Mg—X) of metal (X) and Mg in a liquid phase is made to react with B in a solid phase at a low temperature to manufacture a superconductor, which contains a large amount of MgB2 potential for MRI, linear motorcar, superconducting cavity, electric power transmission cable, high-magnetic field magnet for medical units, electric power storage (SMES), and the like and is formed in the shape of bulk, wire, and foil, by heat treatment performed at a low temperature for a short time and at low cost.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: June 2, 2009
    Assignee: National Institute for Materials Science
    Inventors: Akihiro Kikuchi, Kiyoshi Inoue, Yasuo Iijima, Yuji Yoshida
  • Patent number: 6546614
    Abstract: The diameter of a first metal tube charged with raw material powder is reduced for obtaining an elementary wire. A plurality of such elementary wires are charged into a second metal tube, which in turn is reduced in diameter for obtaining a round first wire having a plurality of first filaments. The first wire is uniaxially compressed thereby obtaining a tape-like second wire having a plurality of second filaments. The second wire is heat treated thereby obtaining an oxide superconducting wire including a plurality of superconductor filaments. The maximum grain size of the raw material powder is smaller than the minor diameter of the first or second filaments.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: April 15, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tetsuyuki Kaneko, Naoki Ayai, Jun Fujikami, Shinichi Kobayashi
  • Patent number: 6335065
    Abstract: A process for centrifugal slip casting a textured hollow tube. A slip made up of a carrier fluid and a suspended powder is introduced into a porous mold which is rotated at a speed sufficient to create a centrifugal force that forces the slip radially outward toward the inner surface of the mold. The suspended powder, which is formed of particles having large dimensional aspect ratios such as particles of superconductive BSCCO, settles in a textured fashion radially outward toward the mold surface. The carrier fluid of the slip passes by capillary action radially outward around the settled particles and into the absorbent mold. A layer of mold release material is preferably centrifugally slip cast to cover the mold inner surface prior to the introduction of the BSCCO slip, and the mold release layer facilitates removal of the BSCCO greenbody from the mold without fracturing.
    Type: Grant
    Filed: November 10, 1999
    Date of Patent: January 1, 2002
    Assignee: Purdue Research Foundation
    Inventors: Greg A. Steinlage, Kevin P. Trumble, Keith J. Bowman
  • Patent number: 6271473
    Abstract: A clad superconductive wire or tape of an oxide superconductive material and a silver-copper alloy base containing 0.05-90 atomic % a copper or a silver alloy. The silver-copper alloy base contains one or more elements selected from the group of Zr, Hf, Al, V, Nb and Ta in amounts of from 0.01-3 atomic %, or contains Au in amount of 0.01-10 atomic %. The silver alloy contains one or more elements selected from the group of Ti, Zr, Hf, V, Nb, Ta, Mg, Ca, Sr and Ba in amounts of from 0.01 to 3 atomic %, or one or more elements selected from the group of Au, Al, Ga, In and Sn in amounts of 0.05 to atomic %. The base material is filled with a Bi-containing oxide of Bi1PbuSrxCayCuzOw wherein u=0-0.3, X=0.8-1.2, y=0.2-1.2, and z=0.8-2.0, and processed to obtain a superconductive wire or tape having enhanced mechanical strength, superconductivity and plastic workability.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: August 7, 2001
    Assignees: Sumitomo Heavy Industries Ltd., National Research Institute for Metals
    Inventors: Yoshiaki Tanaka, Tomoyuki Yanagiya, Fumiaki Matsumoto, Masao Fukutomi, Toshihisa Asano, Kazunori Komori, Hiroshi Maeda
  • Patent number: 6265354
    Abstract: The present invention provides a method to prepare a (Bi,Pb)SrCaCuO-2223 superconductor, in particular a (Bi,Pb)SrCaCuO-2223 superconducting wire with improved critical current density at reduced cost. In the method of preparing a (Bi,Pb)SrCaCuO-2223 superconducting wire comprising the steps of filling precursor powder into a metal sheath, working the same into a wire by performing deformation processing in this state, and heat treating the wire, the precursor powder is prepared from a powder containing a fully doped 2212 phase and a powder containing an under-doped 2212 phase. This precursor powder provides the advantage of better texture formation, faster and more homogeneous reaction to form the 2223 phase, and improved connectivity between the 2223 grains during the heat treatment process, leading to improved critical current density.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: July 24, 2001
    Inventor: Hengning Wu
  • Patent number: 6246007
    Abstract: A clad superconductive wire or tape of an oxide superconductive material and a silver-copper alloy base containing 0.05-90 atomic % copper or a silver alloy. The silver-copper alloy base contains one or more elements selected from the group of Zr, Hf, Al, V, Nb and Ta in amounts of from 0.01-3 atomic %, or contains Au in amount of 0.01-10 atomic %. The silver alloy contains one or more elements selected from the group of Ti, Zr, Hf, V, Nb, Ta, Mg, Ca, Sr and Ba in amounts of from 0.01 to 3 atomic %, or one or more elements selected from the group of Au, Al, Ga, In and Sn in amounts of 0.05 to atomic %. The base material is filled with a Bi-containing oxide of Bi1PbuSrxCayCuzOw wherein u=0-0.3, X=0.8-1.2, y=0.2-1.2, and z=0.8-2.0, and processed to obtain a superconductive wire or tape having enhanced mechanical strength, superconductivity and plastic workability.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: June 12, 2001
    Assignees: Sumitomo Heavy Industries, Ltd., National Research Institute for Metals
    Inventors: Yoshiaki Tanaka, Tomoyuki Yanagiya, Fumiaki Matsumoto, Masao Fukutomi, Toshihisa Asano, Kazunori Komori, Hiroshi Maeda
  • Patent number: 6221813
    Abstract: The invention relates to a process for producing a shaped body, in which a mixture of oxidic starting powders or a superconducting material, which comprises at least 30% by volume of platelet-shaped primary particles and has such a composition that a high-temperature superconducting material is formed on later, suitable thermal treatment, is comminuted by milling, shearing and/or rolling in such a way that the comminuted powder has a powder particle size distribution having a d90 of ≦20 &mgr;m, and in which the powders which have been comminuted in this way are isostatically compacted by the dry bag method.
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: April 24, 2001
    Assignee: Aventis Research & Technologies GmbH & Co. KG
    Inventors: Günther Riedel, Jürgen Neumann, Joachim Bock, Stephan Gauss
  • Patent number: 6194352
    Abstract: A method for preparing an oxide superconductor cable includes transposing a plurality of oxide superconductor strands along a longitudinal axis so as to form a cable and exposing the cable to a two step heat treatment after cabling of the oxide strands, the heat treatment comprising, (a) heating the cable to and maintaining the cable at a first temperature sufficient to partially melt the article, such that a liquid phase co-exists with the desired oxide superconductor phase; and (b) cooling the cable to and maintaining the cable at a second temperature sufficient to substantially transform the liquid phase into the desired oxide superconductor.
    Type: Grant
    Filed: November 7, 1995
    Date of Patent: February 27, 2001
    Assignee: American Superconductor Corporation
    Inventors: Gilbert N. Riley, Jr., Jeffrey M. Seuntjens, William L. Barnes, Gregory L. Snitchler, Alexander Otto
  • Patent number: 6143697
    Abstract: A method for producing a superconducting thick film involves the steps of forming a thick layer comprising a superconducting material on a substrate; firing the thick layer formed on the substrate; subjecting the fired thick layer to cold isostatic pressing; and refiring the thick layer subjected to cold isostatic pressing.
    Type: Grant
    Filed: August 10, 1999
    Date of Patent: November 7, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tsutomu Tatekawa, Yuji Kintaka, Akio Oota
  • Patent number: 6080703
    Abstract: A method for producing a high temperature superconductor system having the composition TlBiBaCaCuO. The system exhibits a T.sub.c of at least 116 K. The method includes the steps of mixing compounds including Tl, Bi, Ba, Ca, Cu, and O to create a mixture. The mixture is heated. The mixture is then cooled.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: June 27, 2000
    Assignee: University Technology Corporation
    Inventors: Allen M. Hermann, Veeraraghavan Badri
  • Patent number: 6051534
    Abstract: A process for producing the 2223 phase of (Pb,Bi)SrCaCuO that is much faster than existing processes has the steps of: calcining a precursor powder mixture while maintaining intimate mixing of this precursor mixture by intermediate grindings during calcination; compressing the calcination product into a consolidated body; and heating the calcination product while maintaining intimate mixing of the calcination product, to form essentially phase pure 2223 (Pb,Bi)SrCaCu). A fast process for making a (Pb,Bi)SrCaCuO part with a high J.sub.c has the steps of: pressing calcined and reacted (Pb,Bi)SrCaCuO powder into a green body having the shaped of the part; and sintering the green body for a selected time, most preferably between 6 and 8 hours, that is long enough to establish superconducting electrical contact between grains of (Pb,Bi)SrCaCuO but short enough to prevent void formation or part shape distortion. The part made by this process has a high density, at least about 4 or 5 g/cm.sup.3.
    Type: Grant
    Filed: April 21, 1993
    Date of Patent: April 18, 2000
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Roy Rayne, Louis E. Toth, Barry A. Bender, Steven H. Lawrence
  • Patent number: 6008163
    Abstract: A process for centrifugal slip casting a textured hollow tube. A slip made up of a carrier fluid and a suspended powder is introduced into a porous mold which is rotated at a speed sufficient to create a centrifugal force that forces the slip radially outward toward the inner surface of the mold. The suspended powder, which is formed of particles having large dimensional aspect ratios such as particles of superconductive BSCCO, settles in a textured fashion radially outward toward the mold surface. The carrier fluid of the slip passes by capillary action radially outward around the settled particles and into the absorbent mold. A layer of mold release material is preferably centrifugally slip cast to cover the mold inner surface prior to the introduction of the BSCCO slip, and the mold release layer facilitates removal of the BSCCO greenbody from the mold without fracturing.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: December 28, 1999
    Assignee: Purdue Research Foundation
    Inventors: Greg A. Steinlage, Kevin P. Trumble, Keith J. Bowman
  • Patent number: 5952272
    Abstract: Hg,Tl-based superconductors are produced by HIPping. A new superconducting phase, having a double (Hg,Tl)-layer and the nominal composition:(Hg.sub.1-x Tl.sub.x).sub.2 (Ba.sub.1-a Sr.sub.a).sub.2 (Ca.sub.1-b Y.sub.b).sub.2 Cu.sub.3 O.sub.zwhere 0.ltoreq.x.ltoreq.0.95, 0.ltoreq.a.ltoreq.1, 0.ltoreq.b.ltoreq.1, and z is sufficient to provide said phase with a resistive and magnetic superconducting transition of 100 K or above, can be produced. Either precursor oxides, or partially or fully reacted mixed oxides, can be used in the HIPping mixture.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: September 14, 1999
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Louis E. Toth, William Lechter, Earl F. Skelton, Michael Osofsky
  • Patent number: 5929001
    Abstract: A method of preparing a high temperature superconductor. A method of preparing a superconductor includes providing a powdered high temperature superconductor and a nanophase material. These components are combined to form a solid compacted mass with the material disposed in the polycrystalline high temperature superconductor. This combined mixture is rapidly heated, forming a dispersion of nanophase size particles without a eutectic reaction. These nanophase particles can have a flat plate or columnar type morphology.
    Type: Grant
    Filed: October 11, 1995
    Date of Patent: July 27, 1999
    Assignee: University of Chicago
    Inventors: Kenneth C. Goretta, Michael T. Lanagan, Dean J. Miller, Suvankar Sengupta, John C. Parker, Jieguang Hu, Uthamalingam Balachandran, Richard W. Siegel, Donglu Shi
  • Patent number: 5877125
    Abstract: Disclosed herein is a method of preparing a bismuth superconductor including the steps of mixing raw materials for forming a bismuth superconductor with each other to obtain mixed powder, heat treating the mixed powder, pulverizing the mixed powder and then covering the mixed powder with a metal sheath. The mixed powder covered with the metal sheath is prepared to have a 2223 composition in a composition of Bi--Sr--Ca--Cu or (Bi,Pb)--Sr--Ca--Cu and to contain a superconducting phase which is mainly composed of a 2212 phase, and is pulverized into a mean particle diameter of not more than 1 .mu.m with no conversion of the 2212 phase to an amorphous state.
    Type: Grant
    Filed: January 20, 1995
    Date of Patent: March 2, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kenichi Sato, Munetsugu Ueyama
  • Patent number: 5840660
    Abstract: Raw material powder for a bismuth oxide superconductor is molded with addition of an organic vehicle, and the molded raw material is heat treated for removing the organic vehicle before the molded raw material is metal-coated. In this heat treatment, conditions not more than those expressed as T=-1.5.times.logH+600 are applied as to relation between temperature (T) and time (H). Thus, phase transformation of 2212 phases mainly composing the raw material is suppressed so that a large amount of 2223 phases having a relatively high critical temperature are formed when heat treatment is performed after metal coating.
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: November 24, 1998
    Assignees: E.I. Du Pont De Nemours And Company, Sumitomo Electric Industries, Ltd.
    Inventors: Munestugu Ueyama, Kenichi Sato, George E. Zahr
  • Patent number: 5807808
    Abstract: In order to obtain a Bi--Sr--Ca--Cu--O or Bi--Pb--Sr--Ca--Cu--O oxide superconducting wire, raw material powder is pulverized to remove particles of non-superconducting phases having large particle sizes based on difference in particle size, and thereafter the raw material powder is covered with a sheath of silver or silver alloy, so that the sheath is subjected to plastic working and the raw material powder covered with the sheath is sintered.
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: September 15, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takeshi Hikata, Kenichi Sato
  • Patent number: 5801126
    Abstract: The process for producing high-T.sub.c superconductors containing thallium, calcium, barium and copper, possibly also lead and/or strontium, provides for a thallium-free precursor to be produced in a first reaction step and this to be then mechanically triturated, subsequently heated to temperatures in the range from 700.degree. to 950.degree. C. and heat treated for a period of at least 3 hours. The mixture is then cooled to ambient temperature and ground again. Finally, it is heat treated at temperatures of from 400.degree. to 500.degree. C. in a stream of pure oxygen. The thallium-free precursor is then triturated with Tl.sub.2 O.sub.3, if desired shaped into a shaped part and then oxidatively fired in a flowing gas atmosphere.
    Type: Grant
    Filed: September 17, 1996
    Date of Patent: September 1, 1998
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Marc Neubacher, Steffen Elschner, Christoph Lang, Christoph Teske, Hans Karl Mueller-Buschbaum
  • Patent number: 5789348
    Abstract: A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: August 4, 1998
    Assignee: Midwest Research Institute
    Inventor: Raghunath Bhattacharya
  • Patent number: 5747425
    Abstract: High T.sub.c superconducting magnetic shields are provided, together with a method of fabricating such shields, wherein the shields exhibit very high critical applied magnetic field values of at least about 50 Gauss at 77 K. In fabrication procedures, a particulate superconducting ceramic oxide (24) (e.g., thallium 2223) is placed within an uniaxial die assembly (10) and subjected to compression while the die is heated via an external heating jacket (26). After formation of a self-sustaining body (24a), the die (10) is additionally heated via the jacket (26). External heating of the die (10) with the superconducting material therein reduces internal stresses within the shield body.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: May 5, 1998
    Assignee: Midwest Superconductivity Inc.
    Inventors: Ying Xin, Wangsong He, Michael S. P. Lucas, Xin Fei, Yi-Han Kao
  • Patent number: 5744427
    Abstract: In a method of preparing a thallium oxide superconductor having components of Tl-Bi-Ca-Sr-Cu-O or Tl-Bi-Pb-Ca-Sr-Cu-O from raw material powder, the raw material powder is subjected to first heat treatment, then exposed to a compressive load, and thereafter subjected to second heat treatment. Thus, a thallium oxide superconductor having a high critical current density can be obtained.
    Type: Grant
    Filed: April 25, 1994
    Date of Patent: April 28, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Yasuko Torii
  • Patent number: 5674814
    Abstract: The present invention is directed to a process for producing high temperature superconducting ceramic materials. More particularly, the present invention is directed to a process that enhances the densification of Bi.sub.1.8 Pb.sub.0.4 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10 "BSCCO" ceramics.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: October 7, 1997
    Assignee: University of Chicago
    Inventors: Michael T. Lanagan, John J. Picciolo, Stephen E. Dorris
  • Patent number: 5661114
    Abstract: A method for preparing a BSCCO-2223 oxide superconducting article includes annealing an oxide superconductor article comprised of BSCCO-2223 oxide superconductor at a temperature selected from the range of about 500.degree. C..ltoreq.T.ltoreq.787.degree. C. and an annealing atmosphere having an oxygen pressure selected from within the region having a lower bound defined by the equation, P.sub.O2 (lower).gtoreq.3.5.times.10.sup.10 exp(-32,000/T+273) and an upper bound defined by the equation, P.sub.O2 (upper).ltoreq.1.1.times.10.sup.12 exp(-32,000/T+273). The article is annealed for a time sufficient to provide at least a 10% increase in critical current density as compared to the critical current density of the pre-anneal oxide superconductor article. An oxide superconductor having the formula Bi.sub.2-y Pb.sub.y Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10+x, where 0.ltoreq.x.ltoreq.1.5 and where 0.ltoreq.y.ltoreq.0.
    Type: Grant
    Filed: February 17, 1994
    Date of Patent: August 26, 1997
    Assignee: American Superconductor Corporation
    Inventors: Alexander Otto, Gilbert N. Riley, Jr., William L. Carter
  • Patent number: 5635456
    Abstract: A method for preparing an oxide superconductor article includes exposing the article after deformation of the article to a final heat treatment having the steps of (a) heating the article at a temperature sufficient to partially melt the article, such that a liquid phase co-exists with the desired oxide superconductor phase; and (b) cooling to and holding the article at a temperature sufficient to transform the liquid phase into the desired oxide superconductor, where no deformation occurs after the final heat treatment. The liquid phase of step (a) wets surfaces of a defect contained within the mixed phase, whereby upon transformation of the liquid in step (b) to the desired oxide superconductor, the defect is healed.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: June 3, 1997
    Assignee: American Superconductor Corporation
    Inventors: Gilbert N. Riley, Jr., Alexander Otto, William L. Carter
  • Patent number: 5627141
    Abstract: In order to obtain a ceramics system superconducting wire, a bulk type ceramics system superconductor or its precursor previously treated to have orientativity in its crystal structure is reduced in diameter in a state charged in a metallic pipe, thereby being elongated, and then heat treated. In the as-formed superconducting wire, crystal orientativity of a bulk formed of the superconductor or its precursor is maintained, whereby it is possible to obtain a superconducting wire having high critical current density. In order to further improve the critical current density, it is effective that the diameter reduction working step and the heat treatment step are alternately repeated a plurality of times.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: May 6, 1997
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kazuhiko Hayashi, Hisao Nonoyama
  • Patent number: 5627140
    Abstract: Enhanced flux pinning in superconductors is achieved by embedding carbon nanotubes into a superconducting matrix. The carbon nanotubes simulate the structure, size and shape of heavy ion induced columnar defects in a superconductor such as Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8+x. The nanotubes survive at treatment temperatures of up to approximately 800.degree. C. both in oxygen containing and in inert atmospheres. The superconducting matrix with nanotubes is heat treated at a lower temperature than the temperature used to treat the best case pure superconductor material.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: May 6, 1997
    Assignees: NEC Research Institute, Inc., Florida State University
    Inventors: Kristian Fossheim, Thomas W. Ebbesen
  • Patent number: 5610123
    Abstract: In a method of preparing a bismuth oxide superconducting wire comprising the steps of filling raw material powder into a metal sheath, working the same into a wire by performing deformation processing in this state, and heat treating the wire, the raw material powder is heat treated before the step of working the raw material powder into a wire by performing deformation processing, so that the ratio of a 2212 phase, containing Bi or (Bi,Pb), Sr, Ca and Cu in composition ratios of about 2:2:1:2, to a 2223 phase, containing Bi or (Bi,Pb), Sr, Ca and Cu in composition ratios of about 2:2:2:3, is 75 to 90:10 to 25, in order to prepare a wire which is excellent in critical current density as well as in critical current.
    Type: Grant
    Filed: February 8, 1995
    Date of Patent: March 11, 1997
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kenichi Sato, Takeshi Hikata, Munetsugu Ueyama
  • Patent number: 5569641
    Abstract: Two-powder processes for the synthesis of superconducting (Bi, Pb)-2223/Ag-clad wires by the oxide-powder-in-the-robe are provided. The first precursor powder, of nominal stoichiometry CaCuO.sub.x, is a solution-synthesized mixture of Ca.sub.0.45 Cu.sub.0.55 O.sub.2 and CaO. Using these oxide precursor mixtures, superconducting tapes with well-aligned grains and reproducible critical current densities J.sub.c in the range of 20,000 to 26,000 A/cm.sup.2 at 75 K in self-field after annealing less than 200 hours were obtained.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: October 29, 1996
    Assignees: University of California, Los Alamos National Laboratory
    Inventor: Michael G. Smith
  • Patent number: 5545610
    Abstract: An oxide-based superconductor ccmprising Tl, Pb, Sr, Ca and Cu or Tl, Pb, Ba, Sr, Ca and Cu, prepared by subjecting a low melting point composition comprising the superconductor-constituting elements and a solid composition comprising the superconductor-constituting elements, prepared in advance, to reaction under melting conditions for the low melting point composition, has distinguished current pass characteristics in a high magnetic field due to improvement of electric contact among grains through reduction of non-superconductor phase, increase in crystal grain sizes (reduction of crystal boundaries), orientation of crystal and cleaning of crystal boundaries.
    Type: Grant
    Filed: September 2, 1993
    Date of Patent: August 13, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Kazutoshi Higashiyama, Toshiya Doi, Takesi Ozawa, Seizi Takeuchi, Tomoichi Kamo, Shinpei Matsuda, Yutaka Yoshida
  • Patent number: 5523285
    Abstract: A process for the preparation of amorphous precursor powders for Pb-doped Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x (2223) includes a freeze-drying process incorporating a splat-freezing step. The process generally includes splat freezing a nitrate solution of Bi, Pb, Sr, Ca, and Cu to form flakes of the solution without any phase separation; grinding the frozen flakes to form a powder; freeze-drying the frozen powder; heating the dried powder to form a dry green precursor powders; denitrating the green-powders; heating the denitrated powders to form phase-clean Bi-2223 powders. The grain boundaries of the 2223 grains appear to be clean, leading to good intergrain contact between 2223 grains.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: June 4, 1996
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Uthamalingam Balachandran
  • Patent number: 5492885
    Abstract: Mercury-thallium based superconductors with the formula Hg.sub.1-x Tl.sub.x Ba.sub.2 (Ca.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.8+.delta. ; change "their preparing method, in particular characterized in that it" to and a method for preparing them. The new superconductors are prepared by reacting respective ternary oxides, such as Ba.sub.2 CuO.sub.3+x and Ca.sub.1-y Sr.sub.y CuO.sub.2, to reduce the formation of an impure phase and by substituting thallium (Ti) a portion of the mercury (Hg) conventionally used in mercury-based superconductors of similar structure, in order to thermally stabilize the superconductor and provide it with a high critical current density characteristic.
    Type: Grant
    Filed: August 17, 1994
    Date of Patent: February 20, 1996
    Assignee: Korea Research Institute of Standards and Science
    Inventors: Yong H. Hur, Yong K. Park, Jong C. Park
  • Patent number: 5478801
    Abstract: The invention relates to a process for producing cylindrical or round parts of high-T.sub.c superconductor material comprising bismuth, strontium, calcium, copper and oxygen. In this process, a pre-prepared finely-divided oxide mixture with organic additives is first introduced at room temperature into a casting mold. The shaped mixture is then converted into the superconducting shaped part by subsequent thermal treatment.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: December 26, 1995
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Christoph Lang, Iris Kullmer, Joachim Bock
  • Patent number: 5439880
    Abstract: A method of preparing a superconducting oxide by combining the metallic elements of the oxide to form an alloy, followed by oxidation of the alloy to form the oxide. Superconducting oxide-metal composites are prepared in which a noble metal phase intimately mixed with the oxide phase results in improved mechanical properties. The superconducting oxides and oxide-metal composites are provided in a variety of useful forms.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: August 8, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Gregory J. Yurek, John B. Vander Sande
  • Patent number: 5413987
    Abstract: A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals, such as nitrate salts of thallium, barium, calcium, and copper, which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of thallium in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity.
    Type: Grant
    Filed: January 24, 1994
    Date of Patent: May 9, 1995
    Assignee: Midwest Research Institute
    Inventors: Raghunath Bhattacharya, Richard D. Blaugher
  • Patent number: 5409888
    Abstract: To produce a high-temperature superconductor of the composition Bi.sub.2 (Sr,Ca).sub.3 Cu.sub.2 O.sub.8+x having a strontium to calcium ratio of 5:1 to 2:1 and a value of x between 0 and 2, the oxides and/or carbonates of bismuth, strontium, calcium and copper are vigorously mixed in a stoichiometric ratio. The mixture is heated at a temperature of 870.degree. to 1100.degree. C. until a homogeneous melt is obtained. The melt is poured into mold and allowed to solidify in them. The cast bodies removed from the molds are annealed for 6 to 30 hours at 780.degree. to 850.degree. C. Finally, the annealed cast bodies are treated for at least 6 hours at temperatures of 600.degree. to 820.degree. C. in an oxygen atmosphere. The cast bodies can be converted into shaped bodies of the desired sizes by mechanical processes before they are annealed. The shape and size of the shaped bodies may also be determined by the shape and dimensioning of the mold used in producing the cast bodies.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: April 25, 1995
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Joachim Bock, Eberhard Preisler
  • Patent number: 5409891
    Abstract: A rotationally symmetrical molded part of a high-temperature superconductor achieves a critical current density of j.sub.c .gtoreq.800 A/cm.sup.2 at a temperature of 77K, by using a powder mixture (8) having the stoichiometric composition of Bi.sub.2+x EA.sub.3 Cu.sub.2 O.sub.y, where -0.15<x<0.4; EA=an alkaline earth metal or a mixture of alkaline earth metals, in particular a mixture of Sr and Ca in the ratio of Sr:Ca=(2+z):(1-z), where 0<x<0.2; 8.ltoreq.y.ltoreq.8.3. With the aid of a conveying chute (9), the powder mixture (8) is brought uniformly at room temperature with a grain size of <50 .mu.m into a silver mold (5) which is arranged inside a rotating fusion mold (4), open at one side, in a furnace (3). Subsequently, the fusion mold (4) is accelerated, heated to 500.degree. C. and held for approximately 30 min at 500.degree. C. After subsequent partial melting at a temperature of T.sub.m K to T.sub.m +6K, where T.sub.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: April 25, 1995
    Assignee: Asea Brown Boveri Ltd.
    Inventors: Thomas Baumann, Peter Unternahrer
  • Patent number: 5407908
    Abstract: A method for manufacturing a Pb-based Cu oxide superconductor. The method includes the steps of mixing powders of a raw material containing at least Pb, Sr, Ce, M, where M is at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu, and Cu in a proportion to have the composition of the formula (I),Pb.sub.a (M.sub.1-x-y Ce.sub.x Sr.sub.y).sub.4 Cu.sub.3-a O.sub.z(I)where M is at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu, and a, x, y, and z denote the numbers which satisfy 0.3.ltoreq.a.ltoreq.0.7, 0<x.ltoreq.0.25, 0.3.ltoreq.y<0.5, 8.5.ltoreq.z.ltoreq.9.5, respectively, forming the mixed powder into a shaped body, and firing the shaped body at a temperature of 900.degree. to 1150.degree. C. in an oxidizing atmosphere.
    Type: Grant
    Filed: July 13, 1993
    Date of Patent: April 18, 1995
    Assignees: International Superconductivity Technology Center, Tohoku Electric Power Company, Incorporated, Central Research Institute of Electric Power Industry, The Furukawa Electric Co., Ltd.
    Inventors: Toshihiko Maeda, Kazuhiro Sakuyama, Shin-ichi Koriyama, Ataru Ichinose, Hisao Yamauchi, Shoji Tanaka
  • Patent number: 5384088
    Abstract: Wire, bulk, film, etc. of a superconductive material is manufactured from a powdery precursor. The superconductive material has a superconductive crystal of 1223 phase and/or 1234 phase as a main component, and the powdery precursor comprises at least 1212 phase as a main component.
    Type: Grant
    Filed: October 23, 1992
    Date of Patent: January 24, 1995
    Assignees: Hitachi Cable, Ltd., Hitachi Ltd.
    Inventors: Junichi Sato, Masahiro Seido, Akira Nomoto, Tomoichi Kamo, Katsuzo Aihara
  • Patent number: 5376623
    Abstract: Unexpected results were obtained when Tl-1223 and Tl=-2223 superconductive materials were annealed at respectively pre-determined annealing temperatures. The optimum annealing temperatures for Tl-1223 and Tl-2223 superconductive materials are found to be 860.degree. C. and 820.degree. C., respectively. By incorporating the optimum annealing temperature and an optimum annealing envirenment, which is expressed in terms of oxygen partial pressure, into the manufacturing process, the present invention presents a method which can substantially increase the critical temperature of thallium based superconductive materials with greatly reduced annealing time and with improved reproducibility, and is thus superior to any method disclosed in the prior art.
    Type: Grant
    Filed: September 7, 1993
    Date of Patent: December 27, 1994
    Assignee: Industrial Technology Research Institute
    Inventors: Ming-Jinn Tsai, Sheng-Feng Wu, Yao-Tsung Huang, Ru-Shi Liu
  • Patent number: 5334579
    Abstract: A process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, Ca).sub.x (.alpha., Dy).sub.1-x Tl.sub.y Cu.sub.1-y O.sub.3-zwherein ".alpha." represents Y or La; the atomic ratio of Ca to Ba is between 1% and 90%; the atomic ratio of Dy to .alpha. is between 1% and 90%; x, y and z are within the ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z<1 respectively; and the expression of (Ba, Ca) and (.alpha., Dy) means that the respective elements occupy predetermined sites in a crystal in a predetermined proportion. The process comprises preparing a material powder, compacting the material powder and then subjecting the resulting compact to a final sintering operation and is characterized in that the material powder is(A) a powder mixture composed of powders selected from a group comprising (i) powders of elemental Ba, Cu, Ca, .alpha., Dy and Tl and (ii) powders of compounds each containing at least one of said elements Ba, Cu, Ca, .
    Type: Grant
    Filed: December 31, 1992
    Date of Patent: August 2, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
  • Patent number: 5332721
    Abstract: An improved technique for the fabrication of thallium-based superconducting oxides, and particularly Tl:Ba:Ca:Cu:O 2223 oxides, is described which allows production of very pure superconductors (>95% 2223 phase) having excellent structural characteristics. The method of the invention involves first forming a self-sustaining body of starting oxides and subjecting this body to a sintering technique wherein the temperature of the body is gradually raised to a maximum level of about 850.degree.-930.degree. C., followed by maintaining the body at this temperature for a period of about 48 hours. The body is then slowly cooled to avoid distortion and loss of superconducting character. Most preferably, the sintering is a two-stage operation, wherein the body is first heated a relatively low rate (e.g., 1.degree.-10.degree. C./min.) to a temperature of about 650.degree.-750.degree. C., followed by faster heating at a higher rate to achieve the maximum sintering temperature.
    Type: Grant
    Filed: October 21, 1992
    Date of Patent: July 26, 1994
    Assignees: Midwest Superconductivity, Inc., The University of Arkansas
    Inventors: Ying Xin, Zhengzhi Sheng, Yufang Li
  • Patent number: 5328892
    Abstract: An oxide superconducting material having a composition represented by a formulaTlSr.sub.2 (Sr.sub.n-x Y.sub.x)Cu.sub.n+1 O.sub.5+2nwherein n=1 or 2 and 0.1.ltoreq.x.ltoreq.n is provided. This material has a high critical current density Jc even by sintering at a relatively low temperature of 850.degree.-880.degree. C.
    Type: Grant
    Filed: September 27, 1989
    Date of Patent: July 12, 1994
    Assignee: NEC Corporation
    Inventors: Takashi Manako, Yuichi Shimakawa, Yoshimi Kubo
  • Patent number: 5324712
    Abstract: A process for producing a high critical temperature bismuth strontium calcium copper oxide superconducting material. An intimate mixture is formed of two superconducting materials. The first material is bismuth strontium calcium copper oxide or (bismuth, lead) strontium calcium copper oxide, and has a bulk critical temperature below about 90K. The second material is a seeding powder of bismuth strontium calcium copper oxide or (bismuth, lead) strontium calcium copper oxide, and includes at least 20 volume percent 2223 phase. The amount of seeding material added to the mixture is selected to result in an amount of 2223 phase in the mixture of about 2-50 weight percent. The mixture is annealed in an oxidizing atmosphere at a temperature of at least about 845.degree. C. and below the melting temperature of the 2223 phase, for a time sufficient to increase the amount of 2223 phase in the mixture.
    Type: Grant
    Filed: August 16, 1991
    Date of Patent: June 28, 1994
    Assignee: GTE Laboratories Incorporated
    Inventor: Sophia R. Su
  • Patent number: 5314867
    Abstract: A process of making high temperature Tl-based superconductors. The process includes the steps of reacting solid Ba--Ca--Cu-oxides with Tl.sub.2 O.sub.3 vapor. The process allows high quality Tl-based superconductors to be easily fabricated.
    Type: Grant
    Filed: July 25, 1991
    Date of Patent: May 24, 1994
    Assignee: University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 5306700
    Abstract: A method is disclosed for fabricating bulk superconducting materials into shaped articles, including ones of relatively large sizes and complex shapes, which have high densities, high integrity, high magnetization and critical current densities. A mixture of superconducting material is completely or substantially melted and the molten material is then cooled to room temperature and ground to a powder. The ground powder is next mixed with a second phase made up of either precursor superconducting powder or a mixture of metallic silver and copper. The resulting mixture is then shaped into an article by conventional ceramic article forming techniques: pressing, extruding, molding or the like. The resulting shaped article is heated to a temperature at which a substantial amount of its content of second phase material is melted, thus facilitating densification of the entire shaped article. The resulting dense specimen is annealed in an appropriate environment while it is being cooled to room temperature.
    Type: Grant
    Filed: September 1, 1992
    Date of Patent: April 26, 1994
    Assignee: The Catholic University of America
    Inventor: Hamid Hojaji